Precise control over the morphology of nanostructures is critical for tailoring their physical and chemical properties. This study addresses the challenge of developing a simple, integrated method for synthesizing both 1D and 2D colloidal Cu nanostructures in a single system, achieving successful tuning of their localized surface plasmon resonance (LSPR) properties. A facile hydrothermal synthesis utilizing potassium iodide (KI) and hexadecylamine (HDA) is presented for controlling Cu nanostructure morphologies. The key to achieving 1D nanowires (NWs) and 2D nanoplates (NPs) depends on the controlled adsorption of HDA molecules and iodide (I-) ions on specific crystal facets. Depending on the morphologies, the resultant Cu nanostructures exhibit tunable LSPR peaks from 558 nm [nanoplates (NPs)] to 590 nm [nanowires (NWs)]. These results pave the way for the scalable and cost-effective production of plasmonic Cu nanostructures with tunable optical properties, holding promise for applications in sensing, catalysis, and photonic devices.

Citations

• Complexation-controlled Cu@Ag core-shell flakes for thermally stable printed electrodes in flexible energy-storage capacitors
  Seokhwan Kim, Geumseong Lee, Ye Chan Lee, Je-Hui Koo, Seonhwa Park, Geon-Tae Hwang, Mahesh Peddigari, Jungho Ryu, Dahye Shin, Kyoung Jin Jung, Kwi-Il Park, Yuho Min
  Chemical Engineering Journal.2026; 540: 177341.     CrossRef

Epitaxial ZnO nanowires (NWs) were synthesized on sapphire (001) substrates using a hydrothermal process. The effects of the pH value of the precursor solution on the structural and optical properties of the resulting NWs was studied. The epitaxial relationship and the domain matching configuration between the sapphire (001) substrate and the as-grown ZnO NWs were determined using synchrotron X-ray diffraction measurements. The (002) plane of wurtzite ZnO NW grows in the surface normal direction parallel to the sapphire (001) direction. However, three types of in-plane domain matching configurations were observed, such as the on-position, 30°-rotated position, and ±8.5°-rotated position relative to the on-position, which might be attributed to inheriting the in-plane domain configuration of the ZnO seed layer.

Highly optical transparent photoelectric devices were realized by using a transparent metal-oxide semiconductor heterojunction of p-type NiO and n-type ZnO. A functional template of ITO nanowires (NWs) was applied to this transparent heterojunction device to enlarge the light-reactive surface. The ITO NWs/n-ZnO/p-NiO heterojunction device provided a significant high rectification ratio of 275 with a considerably low reverse saturation current of 0.2 nA. The optical transparency was about 80% for visible wavelengths, however showed an excellent blocking UV light. The nanostructured transparent heterojunction devices were applied for UV photodetectors to show ultra fast photoresponses with a rise time of 8.3 mS and a fall time of 20 ms, respectively. We suggest this transparent and super-performing UV responser can practically applied in transparent electronics and smart window applications.

ZnO nanowires were grown by hydrothermal synthesis process and piezoelectric poly vinylidenefluoride (PVDF) was then coated on top of the ZnO-nanowires by spray-coating technique. Thecomposite layer of ZnO-nanowires/PVDF was applied to an energy harvesting device based onpiezoelectric-conversion mechanism. A defined mechanical force was given to the nanogenerator device toevaluate their electric power generation characteristics, where output current density and voltage wereexamined. Electric power generation property of the ZnO-nanowires/PVDF based nanogenerator devicewas compared to that of the nanogenerator device with ZnO-nanowires as single active layer. Effect ofthe ZnO-nanowires on improvement of power generation was discussed to examine its feasibility for thenanogenerator device.

Hydrothermal synthesis technique could be carried out for growth of ZnO nanowires atrelatively low process temperature, and it could be freely utilized with various substrates for fabricationprocess of functional electronic devices. However, it has also a demerit of relatively slow growthcharacteristics of the resulting ZnO nanowires. In this paper, an external DC bias of positive and negative0.5 [V] was applied in the hydrothermal synthesis process for 2∼8 [h] to prepare ZnO nanowires on aseed layer of AZO with high electrical conductivity. Growth characteristics of the synthesized ZnOnanowires were analyzed by FE-SEM. Material property of the grown ZnO nanowires was examined byPL analysis. The ZnO nanowires grown with positive bias revealed distinctively enhanced growthcharacteristics, and they showed a typical material property of ZnO.

Fe3O4(magnetite) having half metallic property attracts great attention material with high curie temperature in spintronics. Fe3O4 thin films and nanowires were grown onto c-Al2O3(0001) at various substrate temperatures. Fe3O4 films deposited from 300 to 600℃ are influenced by thermal stress induced from mismatch of thermal expansion coefficient between Fe3O4 and Al2O3 (0001) substrate. The Fe3O4 nanowires grown at 640℃ showed a diameter of 130 nm and a length of 2-10 μm. The nanowire arrays fabricated by pulsed laser deposition technique have high coercivity(Hc) of 608 Oe and Squareness(Mr/Ms) of 0.68 in perpendicular direction.

Single crystalline Au nanowires were successfully synthesized in a tube-type furnace. The Au nanowires were grown by vapor phase synthesis technique using solid-liquid-solid (SLS) mechanism on substrates of corning glass and Si wafer. Prior to Au nanowire synthesis, Au thin film served as both catalyst and source for Au nanowire was prepared by sputtering process. Average length of the grown Au nanowires was approximately 1 μm on both the corning glass and Si wafer substrates, while the diameter and the density of which were dependent on the thickness of the Au thin film. To induce a super-saturated states for the Au particle catalyst and Au molecules during the Au nanowire synthesis, thickness of the Au catalyst thin film was fixed to 10 nm or 20 nm. Additionally, synthesis of the Au nanowires was carried out without introducing carrier gas in the tube furnace, and synthesis temperature was varied to investigate the temperature effect on the resulting Au nanowire characteristics.